>The results of this study also indicate that mite-sampling data can be
>highly variable. Mite numbers from sticky board samples were found to vary
>by as much as 250% in as little as two weeks.  

I've seen alcohol wash vary by as much as 850% _in one hive_ and my recent 
observations seem to indicate that in lightly infested hives, at any rate, 
mature mites tend to drop in patterns, rather than randomly under the cluster.  

That is tentative, of course since I don't know exactly where the cluster is in 
these heavy hives right now, and any patches of brood -- and I have not looked,
 but the debris on the board and experience makes me think that there are 
mite "hot" spots in the cluster.  (Of course, that is why we try to sample from an 
area of brood, but it may not be that simple). 

Moreover, in a three and four storey hive like mine, some falling mites could well be 
getting hung up in burr comb on the way down, as my frames do not all hang 
perfectly scraped and exactly above one another the way they do in most BEE-L 
reader's and all researchers' hives.  When I do this, it is not an exact process, 
but rather a medley of errors which hopefully cancel and do not obscure the signal.


> These data make it difficult to set mite number thresholds for beekeepers to
> use when making management decisions for colony treatment.

That is why single measurements or even single studies are not very reliable, and 
I believe that the useful thresholds are set based on large samples with outliers 
thrown out and with a margin of safety (grain of salt) added.

Some published thresholds IMO skate close to the edge and beekeepers 
believe them at their peril.  Prudent beekeepers add an additional margin of safety.

That said, I am starting to conclude that my mite loads were not as high as I 
thought going in, judging by the mite mortality.  I had a poor record in the days 
before fogging with oxalic because I was just beginning to monitor when the 
machine showed up and we blasted them.

Since then, I have been digging and writing and pondering, and recording my 
findings and thoughts at http://www.honeybeeworld.com/diary

Comments and criticisms are welcome.

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